DJT will NOT be re-elected in 2020. Will likely be Impeached and possibly Convicted (of multiple crimes real or imagined) and Removed; President Pelosi will then take the reins of government until 2020 when she will be elected by overwhelming acclaim beginning the transition of the US into a full blown Socialist Regime of the worst sort (as if their were any other) ...
Not enough time for Pelousi to do so to Trump and then try to get Pence impeached and removed...at best they can try to neuter Pence, but they still need to convince the Senate to remove Trump.